package com.fingard.util;

import org.apache.xmlbeans.impl.util.Base64;
import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;

import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
import java.io.*;
import java.math.BigInteger;
import java.security.*;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.InvalidKeySpecException;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.RSAPublicKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.util.Map;

/**
 * Description: [DSP]
 * Created on 19/04/02
 *
 * @author <a href="mailto:zhangxw@fingard.com.cn">ross</a>
 * @version 1.0
 * Copyright (c) 2019 FinGard
 */
public class RSAEncryptHelper {

    /**
     * 字节数据转字符串专用集合
     */
    private static final char[] HEX_CHAR = {'0', '1', '2', '3', '4', '5', '6',
            '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'};

    /**
     * 随机生成密钥对
     */
    public static void genKeyPair(String filePath, int keysize) {
        // KeyPairGenerator类用于生成公钥和私钥对，基于RSA算法生成对象
        KeyPairGenerator keyPairGen = null;
        try {
            keyPairGen = KeyPairGenerator.getInstance("RSA");
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        }
        // 初始化密钥对生成器，密钥大小为96-1024位
        keyPairGen.initialize(keysize, new SecureRandom());
        // 生成一个密钥对，保存在keyPair中
        KeyPair keyPair = keyPairGen.generateKeyPair();
        // 得到私钥
        RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();
        // 得到公钥
        RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();
        try {
            // 得到公钥字符串
            String publicKeyString = (new BASE64Encoder()).encode(publicKey.getEncoded());
            // 得到私钥字符串
            String privateKeyString = (new BASE64Encoder()).encode(privateKey.getEncoded());
            // 将密钥对写入到文件
            FileWriter pubfw = new FileWriter(filePath + "/publicKey.keystore");
            FileWriter prifw = new FileWriter(filePath + "/privateKey.keystore");
            BufferedWriter pubbw = new BufferedWriter(pubfw);
            BufferedWriter pribw = new BufferedWriter(prifw);
            pubbw.write(publicKeyString);
            pribw.write(privateKeyString);
            pubbw.flush();
            pubbw.close();
            pubfw.close();
            pribw.flush();
            pribw.close();
            prifw.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**
     * 从文件中输入流中加载公钥
     *
     * @param path 公钥文件名
     * @throws Exception 加载公钥时产生的异常
     */
    public static String loadPublicKeyByFile(String path) throws Exception {
        try {
            BufferedReader br = new BufferedReader(new FileReader(path));
            String readLine = null;
            StringBuilder sb = new StringBuilder();
            while ((readLine = br.readLine()) != null) {
                sb.append(readLine);
            }
            br.close();
            return sb.toString();
        } catch (IOException e) {
            throw new Exception("公钥数据流读取错误");
        } catch (NullPointerException e) {
            throw new Exception("公钥输入流为空");
        }
    }

    /**
     * 从字符串中加载公钥
     *
     * @param publicKeyStr 公钥数据字符串
     * @throws Exception 加载公钥时产生的异常
     */
    public static RSAPublicKey loadPublicKeyByStr(String publicKeyStr) throws Exception {
        try {
            byte[] buffer = (new BASE64Decoder()).decodeBuffer(publicKeyStr);
            KeyFactory keyFactory = KeyFactory.getInstance("RSA");
            X509EncodedKeySpec keySpec = new X509EncodedKeySpec(buffer);
            return (RSAPublicKey) keyFactory.generatePublic(keySpec);
        } catch (NoSuchAlgorithmException e) {
            throw new Exception("无此算法");
        } catch (InvalidKeySpecException e) {
            throw new Exception("公钥非法");
        } catch (NullPointerException e) {
            throw new Exception("公钥数据为空");
        }
    }

    /**
     * 从文件中加载私钥
     *
     * @param path 私钥文件名
     * @return 是否成功
     * @throws Exception
     */
    public static String loadPrivateKeyByFile(String path) throws Exception {
        try {
            BufferedReader br = new BufferedReader(new FileReader(path));
            String readLine = null;
            StringBuilder sb = new StringBuilder();
            while ((readLine = br.readLine()) != null) {
                sb.append(readLine);
            }
            br.close();
            return sb.toString();
        } catch (IOException e) {
            throw new Exception("私钥数据读取错误");
        } catch (NullPointerException e) {
            throw new Exception("私钥输入流为空");
        }
    }

    public static RSAPrivateKey loadPrivateKeyByStr(String privateKeyStr) throws Exception {
        try {
            byte[] buffer = (new BASE64Decoder()).decodeBuffer(privateKeyStr);
            PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(buffer);
            KeyFactory keyFactory = KeyFactory.getInstance("RSA");
            return (RSAPrivateKey) keyFactory.generatePrivate(keySpec);
        } catch (NoSuchAlgorithmException e) {
            throw new Exception("无此算法");
        } catch (InvalidKeySpecException e) {
            throw new Exception("私钥非法");
        } catch (NullPointerException e) {
            throw new Exception("私钥数据为空");
        }
    }

    /**
     * 公钥加密过程
     *
     * @param publicKey     公钥
     * @param plainTextData 明文数据
     * @return
     * @throws Exception 加密过程中的异常信息
     */
    public static byte[] encrypt(RSAPublicKey publicKey, byte[] plainTextData) throws Exception {
        if (publicKey == null) {
            throw new Exception("加密公钥为空, 请设置");
        }
        Cipher cipher = null;
        try {
            // 使用默认RSA
            cipher = Cipher.getInstance("RSA");
            // cipher= Cipher.getInstance("RSA", new BouncyCastleProvider());
            cipher.init(Cipher.ENCRYPT_MODE, publicKey);
            byte[] output = cipher.doFinal(plainTextData);
            return output;
        } catch (NoSuchAlgorithmException e) {
            throw new Exception("无此加密算法");
        } catch (NoSuchPaddingException e) {
            e.printStackTrace();
            return null;
        } catch (InvalidKeyException e) {
            throw new Exception("加密公钥非法,请检查");
        } catch (IllegalBlockSizeException e) {
            throw new Exception("明文长度非法");
        } catch (BadPaddingException e) {
            throw new Exception("明文数据已损坏");
        }
    }

    /**
     * 公钥加密过程
     *
     * @param publicKey     公钥
     * @param plainTextData 明文数据
     * @param charsetName   字符编码
     * @return
     * @throws Exception 加密过程中的异常信息
     */
    public static String encrypt(RSAPublicKey publicKey, String plainTextData, String charsetName) throws Exception {
        if (publicKey == null) {
            throw new Exception("加密公钥为空, 请设置");
        }
        Cipher cipher = null;
        try {
            // 使用默认RSA
            cipher = Cipher.getInstance("RSA");
            // cipher= Cipher.getInstance("RSA", new BouncyCastleProvider());
            cipher.init(Cipher.ENCRYPT_MODE, publicKey);
            byte[] output = cipher.doFinal(plainTextData.getBytes(charsetName));
            return (new BASE64Encoder()).encode(output);
        } catch (NoSuchAlgorithmException e) {
            throw new Exception("无此加密算法");
        } catch (NoSuchPaddingException e) {
            e.printStackTrace();
            return null;
        } catch (InvalidKeyException e) {
            throw new Exception("加密公钥非法,请检查");
        } catch (IllegalBlockSizeException e) {
            throw new Exception("明文长度非法");
        } catch (BadPaddingException e) {
            throw new Exception("明文数据已损坏");
        }
    }

    /**
     * 私钥加密过程
     *
     * @param privateKey    私钥
     * @param plainTextData 明文数据
     * @return
     * @throws Exception 加密过程中的异常信息
     */
    public static byte[] encrypt(RSAPrivateKey privateKey, byte[] plainTextData) throws Exception {
        if (privateKey == null) {
            throw new Exception("加密私钥为空, 请设置");
        }
        Cipher cipher = null;
        try {
            // 使用默认RSA
            cipher = Cipher.getInstance("RSA");
            cipher.init(Cipher.ENCRYPT_MODE, privateKey);
            byte[] output = cipher.doFinal(plainTextData);
            return output;
        } catch (NoSuchAlgorithmException e) {
            throw new Exception("无此加密算法");
        } catch (NoSuchPaddingException e) {
            e.printStackTrace();
            return null;
        } catch (InvalidKeyException e) {
            throw new Exception("加密私钥非法,请检查");
        } catch (IllegalBlockSizeException e) {
            throw new Exception("明文长度非法");
        } catch (BadPaddingException e) {
            throw new Exception("明文数据已损坏");
        }
    }

    /**
     * 私钥加密过程
     *
     * @param privateKey    私钥
     * @param plainTextData 明文数据
     * @param charsetName   字符编码
     * @return
     * @throws Exception 加密过程中的异常信息
     */
    public static String encrypt(RSAPrivateKey privateKey, String plainTextData, String charsetName) throws Exception {
        if (privateKey == null) {
            throw new Exception("加密私钥为空, 请设置");
        }
        Cipher cipher = null;
        try {
            // 使用默认RSA
            cipher = Cipher.getInstance("RSA");
            cipher.init(Cipher.ENCRYPT_MODE, privateKey);
            byte[] output = cipher.doFinal(plainTextData.getBytes(charsetName));
            return (new BASE64Encoder()).encode(output);
        } catch (NoSuchAlgorithmException e) {
            throw new Exception("无此加密算法");
        } catch (NoSuchPaddingException e) {
            e.printStackTrace();
            return null;
        } catch (InvalidKeyException e) {
            throw new Exception("加密私钥非法,请检查");
        } catch (IllegalBlockSizeException e) {
            throw new Exception("明文长度非法");
        } catch (BadPaddingException e) {
            throw new Exception("明文数据已损坏");
        }
    }

    /**
     * 私钥解密过程
     *
     * @param privateKey 私钥
     * @param cipherData 密文数据
     * @return 明文
     * @throws Exception 解密过程中的异常信息
     */
    public static byte[] decrypt(RSAPrivateKey privateKey, byte[] cipherData) throws Exception {
        if (privateKey == null) {
            throw new Exception("解密私钥为空, 请设置");
        }
        Cipher cipher = null;
        try {
            // 使用默认RSA
            cipher = Cipher.getInstance("RSA");
            // cipher= Cipher.getInstance("RSA", new BouncyCastleProvider());
            cipher.init(Cipher.DECRYPT_MODE, privateKey);
            byte[] output = cipher.doFinal(cipherData);
            return output;
        } catch (NoSuchAlgorithmException e) {
            throw new Exception("无此解密算法");
        } catch (NoSuchPaddingException e) {
            e.printStackTrace();
            return null;
        } catch (InvalidKeyException e) {
            throw new Exception("解密私钥非法,请检查");
        } catch (IllegalBlockSizeException e) {
            throw new Exception("密文长度非法");
        } catch (BadPaddingException e) {
            throw new Exception("密文数据已损坏");
        }
    }

    /**
     * 私钥解密过程
     *
     * @param privateKey  私钥
     * @param cipherData  密文数据
     * @param charsetName 字符编码
     * @return 明文
     * @throws Exception 解密过程中的异常信息
     */
    public static String decrypt(RSAPrivateKey privateKey, String cipherData, String charsetName) throws Exception {
        if (privateKey == null) {
            throw new Exception("解密私钥为空, 请设置");
        }
        Cipher cipher = null;
        try {
            // 使用默认RSA
            cipher = Cipher.getInstance("RSA");
            // cipher= Cipher.getInstance("RSA", new BouncyCastleProvider());
            cipher.init(Cipher.DECRYPT_MODE, privateKey);
            byte[] output = cipher.doFinal((new BASE64Decoder()).decodeBuffer(cipherData));
            return new String(output, charsetName);
        } catch (NoSuchAlgorithmException e) {
            throw new Exception("无此解密算法");
        } catch (NoSuchPaddingException e) {
            e.printStackTrace();
            return null;
        } catch (InvalidKeyException e) {
            throw new Exception("解密私钥非法,请检查");
        } catch (IllegalBlockSizeException e) {
            throw new Exception("密文长度非法");
        } catch (BadPaddingException e) {
            throw new Exception("密文数据已损坏");
        }
    }

    /**
     * 公钥解密过程
     *
     * @param publicKey  公钥
     * @param cipherData 密文数据
     * @return 明文
     * @throws Exception 解密过程中的异常信息
     */
    public static byte[] decrypt(RSAPublicKey publicKey, byte[] cipherData) throws Exception {
        if (publicKey == null) {
            throw new Exception("解密公钥为空, 请设置");
        }
        Cipher cipher = null;
        try {
            // 使用默认RSA
            cipher = Cipher.getInstance("RSA");
            // cipher= Cipher.getInstance("RSA", new BouncyCastleProvider());
            cipher.init(Cipher.DECRYPT_MODE, publicKey);
            byte[] output = cipher.doFinal(cipherData);
            return output;
        } catch (NoSuchAlgorithmException e) {
            throw new Exception("无此解密算法");
        } catch (NoSuchPaddingException e) {
            e.printStackTrace();
            return null;
        } catch (InvalidKeyException e) {
            throw new Exception("解密公钥非法,请检查");
        } catch (IllegalBlockSizeException e) {
            throw new Exception("密文长度非法");
        } catch (BadPaddingException e) {
            throw new Exception("密文数据已损坏");
        }
    }

    /**
     * 公钥解密过程
     *
     * @param publicKey   公钥
     * @param cipherData  密文数据
     * @param charsetName 字符编码
     * @return 明文
     * @throws Exception 解密过程中的异常信息
     */
    public static String decrypt(RSAPublicKey publicKey, String cipherData, String charsetName) throws Exception {
        if (publicKey == null) {
            throw new Exception("解密公钥为空, 请设置");
        }
        Cipher cipher = null;
        try {
            // 使用默认RSA
            cipher = Cipher.getInstance("RSA");
            // cipher= Cipher.getInstance("RSA", new BouncyCastleProvider());
            cipher.init(Cipher.DECRYPT_MODE, publicKey);
            byte[] output = cipher.doFinal((new BASE64Decoder()).decodeBuffer(cipherData));
            return new String(output, charsetName);
        } catch (NoSuchAlgorithmException e) {
            throw new Exception("无此解密算法");
        } catch (NoSuchPaddingException e) {
            e.printStackTrace();
            return null;
        } catch (InvalidKeyException e) {
            throw new Exception("解密公钥非法,请检查");
        } catch (IllegalBlockSizeException e) {
            throw new Exception("密文长度非法");
        } catch (BadPaddingException e) {
            throw new Exception("密文数据已损坏");
        }


    }

//    public static void main(String[] args) throws Exception {
//        genKeyPair("D:/",512);
//        String publicKeyStr = loadPublicKeyByFile("E:/publicKey.keystore") ;
//        String privateKeyStr = loadPrivateKeyByFile("E:/privateKey.keystore");
//        RSAPrivateKey rsaPrivateKey = loadPrivateKeyByStr(privateKeyStr);
//        RSAPublicKey rsaPublicKey = loadPublicKeyByStr(publicKeyStr);
////        String plainTextData = "8246A4D3F35FB1725DF5D43F94F5889ADC2AE5CE186CF2A7EADC7969A3D89F04sssss121212122222222222222222222222222222222222222222aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaSoQ5ge0FJ82RPNriht2wCyFCAgPG1gLq5IhpBxyoMgc2asdadsdsssssssssssssssssssssssssssssdsdsaaaaadddaaaaaaaaaaaaaaaaadssddsdsd112ssssssssssssssssssssssssssssssssssss121212122222222222222222222222222222222222222222aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaSoQ5ge0FJ82RPNriht2wCyFCAgPG1gLq5IhpBxyoMgc2asdadsdsssssssssssssssssssssssssssssdsdsaaaaadddaaaaaaaaaaaaaaaaadssddsdsd112ssssssssssssssssssssssssssssssssssss121212122222222222222222222222222222222222222222aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaSoQ5ge0FJ82RPNriht2wCyFCAgPG1gLq5IhpBxyoMgc2asdadsdsssssssssssssssssssssssssssssdsdsaaaaadddaaaaaaaaaaaaaaaaadssddsdsd112ssssssssssssssssssssssssssssssssssss121212122222222222222222222222222222222222222222aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaSoQ5ge0FJ82RPNriht2wCyFCAgPG1gLq5IhpBxyoMgc2asdadsdsssssssssssssssssssssssssssssdsdsaaaaaddd";
//        String plainTextData ="8246A4D3F35FB1725DF5D43F94F5889ADC2AE5CE186CF2A7EADC7969A3D89F04";
//        String cipherData = encrypt(rsaPublicKey, plainTextData, "GBK");
//        System.out.println("cipherData：" + cipherData);
//        String plainData = decrypt(rsaPrivateKey, cipherData, "GBK");
//        System.out.println("plainData：" + plainData);
//    }


    /**
     * 字节数据转十六进制字符串
     *
     * @param data 输入数据
     * @return 十六进制内容
     */
    public static String byteArrayToString(byte[] data) {
        StringBuilder stringBuilder = new StringBuilder();
        for (int i = 0; i < data.length; i++) {
            // 取出字节的高四位 作为索引得到相应的十六进制标识符 注意无符号右移
            stringBuilder.append(HEX_CHAR[(data[i] & 0xf0) >>> 4]);
            // 取出字节的低四位 作为索引得到相应的十六进制标识符
            stringBuilder.append(HEX_CHAR[(data[i] & 0x0f)]);
            if (i < data.length - 1) {
                stringBuilder.append(' ');
            }
        }
        return stringBuilder.toString();
    }

    /**
     * 压缩 并 RSA+ BASE64加密
     *  ①按字符集转成成子节码
     * @param plainTextData
     * @param charsetName
     * @param publicKey
     * @return
     * @throws Exception
     */
    public static String compressAndRSAPlusBase64Encrypt(String plainTextData,String charsetName, String publicKey) throws Exception {

        //压缩s
        byte[] zipDataByteArr = GZIPUtils.compress(plainTextData,charsetName);

        //RSA加密
        byte[] rsaEncryptDataByteArr = RSAUtil.encryptByPublicKey(zipDataByteArr, publicKey);

        //BASE64加密
        String result = new String(Base64.encode(rsaEncryptDataByteArr), charsetName);

        return result;
    }



    /**
     *  ③RSA解密
     * @param encryptedData
     * @param charsetName
     * @param privateKey
     * @return
     * @throws Exception
     */
    public static String base64PlusRSADecryptAndUncompress(String encryptedData,String charsetName, String privateKey) throws Exception {

        byte[] base64DecryptDateArr = Base64.decode(encryptedData.getBytes(charsetName));

        //RSA 解密
        byte[] rsaDecryptData = RSAUtil.decryptByPrivateKey(base64DecryptDateArr,privateKey);

        String result = GZIPUtils.uncompressToString(rsaDecryptData, charsetName);

        return result;
    }

    public static void main(String[] args) throws Exception {
        Map<String, Object> keyPairMap = RSAUtil.genKeyPair();
        String privateKey = RSAUtil.getPrivateKey(keyPairMap);
        String publicKey = RSAUtil.getPublicKey(keyPairMap);
        String text = "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";
        System.out.println("------------------------------------------------------------------");
        System.out.println("privateKey = [" + privateKey + "]");
        System.out.println("publicKey = [" + publicKey + "]");


        System.out.println("------------------------------------------------------------------");
        String encryptStr = compressAndRSAPlusBase64Encrypt(text,"utf-8", publicKey);
        System.out.println("encryptStr = [" + encryptStr + "]");


        System.out.println("------------------------------------------------------------------");
        String decryptStr = base64PlusRSADecryptAndUncompress(encryptStr,"utf-8", privateKey);
        System.out.println("decryptStr = [" + decryptStr + "]");

        System.out.println("------------------------------------------------------------------");
        System.out.println(text.equals(decryptStr));


    }
}
